Conventional filtering systems, such as bag filters, are directed to filtering dust, dirt, or other solid particles from air or other gaseous media.
However, removing fine particulate solids, such as fly ash from a gasifier, at high temperatures and pressures produces a gas stream that is sufficiently clean so as to be recycled to compressors or power recovery turbines.
Conventional filters in high temperature fly ash service experience high pressure drops across the filters; poor reliability since the filters tend to fail, collapse, and/or tear; and persistent reentrainment of the finely divided fly ash in the filter vessel. Also, the fly ash that is collected on the filter is difficult to remove from the vessel due to the cohesiveness properties of the finely divided fly ash.
The present invention is directed to overcoming these problems in the prior art.
Applicants are not aware of any prior art which, in their judgment as persons skilled in this particular art, would anticipate or render obvious the present invention. However, for the purpose of fully developing the background of the invention, and establishing the state of requisite art, the following art is set forth: U.S. Pat. Nos. 4,227,903; 3,256,679; 4,264,345; 4,220,457; 4,521,231; 4,344,781 and 4,398,931.